Answer:(9y-7)(9y+7)
Step-by-step explanation:
81y^2-49
=(9y)^2-(7)^2
=(9y-7)(9y+7)
Answer:
15
Step-by-step explanation:
Using the formular, Sn = n/2(2a + (n - 1)d)
where, n = 6: Sn = 6/2( -20 + 5(3)) = 3(15 - 20)
∴ Sn = 15
Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Algebra I</u>
<u>Algebra II</u>
- Distance Formula:

Step-by-step explanation:
<u>Step 1: Define</u>
Point (11, 4) → x₁ = 11, y₁ = 4
Point (5, 8) → x₂ = 5, y₂ = 8
<u>Step 2: Find distance </u><em><u>d</u></em>
Simply plug in the 2 coordinates into the distance formula to find distance <em>d</em>
- Substitute in points [Distance Formula]:

- [√Radical] (Parenthesis) Subtract:

- [√Radical] Evaluate exponents:

- [√Radical] Add:

- [√Radical] Simplify:

Assuming your first equation is y = 5x+9, the equations describe lines that are coincident.
_____
Multiplying the second equation by -1, it becomes y = 5x+9, the same as the first equation.
Answer:
22
Step-by-step explanation:
10^2-9(9)+3
100-81+3
19+3
22